In the printing industry, waste material is removed from rollers by using a wiper blade. The wiper blade includes a tip for engaging a rotating roller to scrape any waste material, typically ink, from the roller.
Typically, waste material scraped off the roller is directed to a collection tray.
It has been common for wiper blades to be formed of rubber tip that is vulcanised onto a steel plate. However, the printing industry has begun to use polyurethane tipped wiper blades because of their useful properties in the removal of certain materials. Also, polyurethane has been found to have desirable wear resistance and resistance to ultraviolet (UV) radiation. However, polyurethane does not vulcanise well.
WO2007/113492 describes an alternative construction of wiper blade and support plate. The support plate includes a jaw that is adapted to receive a corresponding part of the wiper blade. The jaw is then crimped so as to grip the wiper blade and secure it to the plate. Adhesive may be applied to one or both of the support plate and the wiper blade to ensure that the wiper blade is secured fast with the support blade.
The solvents used in printing inks cause the wiper blades to wear and therefore the blades must be replaced from time to time. Whilst the device described in WO2007/113492 does provide an alternative to vulcanisation for attaching the blade to the support plate, nevertheless, when the blade is worn and needs to be changed, the whole device must be removed from the printer. This involves removing a plurality of bolts (fifteen for example), each of which is likely to need to be cleaned of ink prior to removal. In most printers, in order to change the blade the waste ink tray into which waste material removed from the roller by the wiper is deposited must be emptied and cleaned to allow the blade assembly to be removed, as the bolts attaching the blade assembly to the tray pass through the tray.
It will be appreciated that changing the wiper blade is a time consuming and messy task.
It would be desirable to provide an improved wiper blade assembly.
EP1112187 describes a waste catchment system which incorporates a wiper assembly comprising a wiper blade attached to a support plate. The blade is configured to receive a lip of a replaceable tray of the waste catchment system so that in use the blade is attached to the replaceable tray.
It would be desirable to provide an improved wiper blade assembly suitable for use with a waste catchment system of the type described in EP1112187.